public abstract class Animal {
  private String name;
  
  // 构造器（不写void）
  void  Animal(String name) {
    this.name = name;
  }
  
  public void speak() {
    System.out.println(name + " makes a sound.");
  }
  // args 命令行参数
  public static void main(String[] args) {
    // System.out.println(args[0]);
    // Animal cat = new Animal("Cat");
    // cat.speak();


  }

    abstract void eat();
}